IATAAviation Net-Zero CO,Transition PathwaysComparative ReviewApril 2024In collaboration with:Air TransportationATAGicctMISSIONPOSSIBLESystems LabAR TRANSPORT ACTION GROUPPARTNERSHIPIncluding contribution from the International Energy Agency (IEA)Executive SummaryTransitioning towards net-zero carbon dioxide (CO2)emissions by 2050 is the greatest challenge for the airHowever,this wide range of possible contributionstransport industry.The aviation industry took thefrom SAF also suggests uncertainty in its globalmomentous decision to reach net zero CO2 emissionssupply,which depends on feedstock availability.in 2021,followed by ICAO member states in 2022.Toproduction costs,as well as supportive action fromachieve this ambition,a basket of measures thatgovernments and financiers.covers aviation energy transition,aircraft technology3)Technology and operation efficiency improvementbreakthrough,operational improvements,market-are expected to have a relatively consistent role inbased measures,and policy supportis required.Giventhe net-zero transition process,togetherthe significant uncertainties associated with thiscontributing to about 30%of the emissionsjourney,there will not be a single universal pathway forreduction in 2050.the sector to reach net zero by 2050.Hence,variousorganizations have developed net-zero CO2pathways4)The emissions savings by hydrogen-and battery-for air transport,including the International Airpowered aircraft are also highly uncertain acrossTransport Association(IATA),the International Energythe roadmaps,depending on whether a strong pro-Agency (IEA).the International Civil Aviationhydrogen policy is adopted as well as a rapidOrganization (ICAO),the Air Transport Action Groupdecline of renewable energy prices,which enables(ATAG),the International Council on Cleanthe fast uptake of the electricity-basedTransportation (ICCT),Mission Possible Partnershiptechnologies.(MPP),DESTINATION 2050,and the U.S.Federal5)The baseline emissions modeled in the roadmapsAviation Administration (FAA).Meanwhile,numeroushave a direct impact on the amount of CO2academic studies on aviation net-zero transition haveemissions that need to be abated by 2050.Thus,also been published in leading scientific journals.apart from the demand growth rates used in aThis report provides the first comprehensive reviewgiven roadmap's baseline,it is also important toof fourteen leading net-zero transition roadmaps forunderstand what is and is not included in thethe aviation sector.By breaking down the massivebaseline (e.g.,energy efficiency improvement inamount of information discussed in those roadmapsthe pipeline versus a frozen technology in 2019).into various aspects for comparison,the report aims6)The demand impact of net-zero transition onto help airlines and stakeholders better understandaviation emissions is modeled only in a handful oftheir critical differences and similarities.Specifically,roadmaps,where a limited emissions reductionthe report compares the selected roadmaps in termscontribution by less than 10%is expected.of their scope,key input assumptions,modeledHowever,a strong demand management policyaviation energy demand,respective CO2 emissions,would double this impact according to the IEA Netand the emissions reduction potential by differentZero 2050 roadmap.mitigation levers.7)To achieve net zero in 2050,almost all the globalSome key findings from this analysis include:roadmaps suggest that the aviation sector will1)Possible pathways to net-zero emissions by 2050need help from market-based measures anddiffer significantly across the roadmaps,carbon removals to bridge the gap (ranging fromdepending on the main vision a roadmap aims to95 MtCO2 to 370 MtCO2)between their residualconvey on how aviation decarbonizationemissions and net zero emissions in 2050.Even iftechnologies and solutions may evolve.Given thecarbon removal technologies are considered andifferent purposes of the roadmaps,one roadmapout-of-sector'mitigation measure,it is still criticalmay put greater importance on certain mitigationto develop these technologies as they will play alevers than others.key role in supplying COz as the feedstock forproducing power-to-liquid (PtL)fuels.2)All roadmaps assume that SAF will be responsiblefor the highest amount of CO2 reductions by 2050,contributing to 24%-70%(with a median value of53%)of the CO2 emissions reductions compared